The average number of people shot in a mass shooting event when the shooter is stopped by law enforcement: 14. The average number of people shot in a mass shooting event when the shooter is stopped by civilians: 2.5. The reason is simple. The armed civilians are there when it started.

Now, he doesn't cite his sources, but any honest cop will tell you that a lot of hurt can come down between the time shooting starts and the law arrives.

Interestingly, it seems that tackling the shooter works best, or at least most often. ("Armed civilians" stop such rampages too, but less often. Correia either got the numbers secondhand or is fudging.)

Presumably, the size difference between beefy vice principal or football team captain versus armed nerd is the cause.

Oh no, rushing the shooter must often getting shot at close range. Two servicemen tried to rush Hasan, didn't work. The Major was taken(shot) down by a armed secureity guard. The shooters pick soft targets locations. Places where no firearms allowed.

Seems that at least some of the shooters target locations where they just know there will be a lot of people, or that they have some personal connection to. Has any shooter explicitly said, say in a note or manifesto, that they targeted Location X because no firearms were allowed?